Incinerator charging cut-off gate

ABSTRACT

A wheeled closure gate for maintaining opened or closed as desired an aperture disposed in a substantially horizontal plane, the gate being shiftable along tracks embracing the aperture which are so relatively inclined with respect to the horizontal plane as to permit the same to be moved upwardly along said tracks by power means into aperture-closing position. The closure gate in this particular instance is of an articulated construction having a pair of hinged-together sections which are foldable upon themselves or &#39;&#39;&#39;&#39;jack-knifed&#39;&#39;&#39;&#39; as the gate is shifted into its open position by suitable power means and are unfolded into coplanar relation by gravity return of the gate into its closed position. When in its jack-knifed open position, the fore section of the gate is upwardly and rearwardly inclined as an extension of the back wall of an incinerator charging hopper with which the gate may be associated to deflect back into the hopper rubbish which would otherwise not be received by the hopper. The tracks for the wheeled gate are of a construction which largely prevents accumulation of debris thereon during charging of the hopper and thus are self-cleaning, the undesired accumulation of debris being further prevented by the aforesaid deflecting shields as well as by locating the tracks inboard of the top edges of the hopper side walls. The gate of the instant construction may be combined with the charging hopper as a unitary assembly thereof.

United States Patent Reiner et al.

[ 1 Dec.26,1972

[54] INCINERATOR CHARGING CUT-OFF GATE [72] Inventors: Joel Russell Reiner, Philadelphia;

William J. Preusch, Southampton; William G. Davenport, Philadelphia,

all of Pa.

[73] Assignee: Beaumont Birch Company, Philadelphia, Pa.

[22] Filed: Oct. 8, 1970 [21] App]. No.: 79,005

[521 US. Cl ..110/173 R, 160/188, 110/176 [51] Int. Cl. ..E05f 11/00 [58] Field ofSearch...160/l88; 110/173 A, 177, 176,

[56] References Cited UNITED STATES PATENTS 3,640,233 2/1972 Reiner et al. ..110/173 R 3,190,637 6/1965 Kummerman ..160/188 3,107,722 10/1963 Larsson ..l60/188 2,932,272 4/1960 Beas ..160/188 2,039,761 5/1936 Weniger.. ...1 10/173 A 3,114,346 12/1963 Dahlin ..l60/188 Primary Examiner-Peter M. Caun Attorney-Edelson & Udell [57] ABSTRACT A wheeled closure gate for maintaining opened or closed as desired an aperture disposed in a substantially horizontal plane, the gate being shiftable along tracks embracing the aperture which are so relatively inclined with respect to the horizontal plane as to permit the same to be moved upwardly along said tracks by power means into aperture-closing position. The closure gate in this particular instance is of an articulated construction having a pair of hinged-together sections which are foldable upon themselves or jackknifed as the gate is shifted into its open position by suitable power means and are unfolded into coplanar relation by gravity return of the gate into its closed position. When in its jack-knifed open position, the fore section of the gate is upwardly and rearwardly inclined as an extension of the back wall of an incinerator charging hopper with which the gate may be associated to deflect back into the hopper rubbish which would otherwise not be received by the hopper. The tracks for. the wheeled gate are of a construction which largely prevents accumulation of debris thereon during charging of the hopper and thus are self-cleaning, the undesired accumulation of debris being further prevented by the aforesaid deflecting shields as well as by locating the tracks inboard of the top edges of the hopper side walls. The gate of the instant construction may be combined with the charging hopper as a unitary assembly thereof.

8 Claims, l6 Drawing Figures PATENTED E925 1972 3 707, 130

sum 3 or 7 I'll 'IIIIIIA 4 4 Qoei Russefl Reiner 8) WHliam Q Preusdv Wilham G Davenport PATENTED I972 3.707.130

SHEET 5 OF 7 a f A I2.

doe\ Rus cH Relner SHEET 6 or 7 PATENTED 25 r My :m p. mu m R MW m r P a BMW m q This invention relates generally to incinerator apparatus and more particularly to improvements in charging cut-off gates for opening and closing as required the hopper through which charges of rubbish to be burned are introduced into the incinerator combustion chamber and in gas relief gates for opening and closing as required exhaust ports through which gases of combustion may be exhausted externally of the incinerator furnace.

Among the specific principal objects of the present invention is to provide a construction of gate which is shiftable into and out of its open and closed position in accordance with the teachings of our co-pending application, Ser. No. 79,038, filed Oct. 8, 1970, now US. Pat. No. 3,640,233, but which is of a more compact design requiring less space for its installation and reduced power for its operation and having a capability of being mounted upon the charging hopper to provide unitary assembly of said hopper and gate.

More specifically, it is an object of the present invention to provide an articulated closure gate which is foldable upon itself as it is shifted from its closed to its opened condition and which may be operated by simple fluid pressure means for opening the same into jack-knifed condition and yet permit it to be unfolded by movement under the force of gravity into substantially flat condition to effectively seal closed the opening with which it is associated.

Still another object of the present invention is to provide an articulated cover operable as a cut-off gate for rubbish being charged into the charging hopper of an incinerator which, when jack-knifed into its open position to permit charging of the hopper, as presents an upwardly and rearwardly inclined flat surface as an extension of the rear wall of the hopper to deflect back into the hopper the charging material which would otherwise spill over the rear wall of the hopper.

A further object of the present invention is to provide a simplified roller wheel track system along which the gate is shifted, which track system requires only a pair of inclined tracks running along opposite sides of the aperture which is to be opened or sealed shut by the gate and a wheel for each track mounted upon the front end of the gate, the arrangement of the wheeled gate and its associated tracks being such that for opening of the gate it is brought into jack-knifed position by movement of its wheeled front end upwardly along the inclined tracks by suitable fluid pressure operated mechanisms located closely adjacent to the rear end of the aperture to which the gate is fitted, while for closing of the gate, by simply releasing it from the hold of the fluid pressure mechanisms, the gate moves by gravity downwardly along the inclined tracks into its flat unfolded closed position over the aperture to be sealed shut.

Still another object of the present invention is to provide a track system for the gravity-retumable jackknife cover which is substantially self-cleaning to maintain it free of debris, this being a feature which is especially desirable where the cover is employed as a charging hopper cut-off gate.

Other objects and advantages of the present invention will be apparent from the following detailed description thereof, it being understood that the invention consists in the construction, combination, location and relative arrangement of parts as hereinafter described, as shown in the accompanying drawings and as finally pointed out in the appended claims.

In the accompanying drawings:

FIG. 1 is a diagrammatic view showing generally in longitudinal cross-section an incinerator having shiftable gates, shown in side elevation, constructed in accordance with and embodying the principles of the present invention;

FIG. 2 is a side elevational view showing the gate of the present invention mounted in position to close off the open top of the charging hopper of the incinerator;

FIG. 3 is a view similar to FIG. 2 but showing the gate drawn into its open, jack-knifed position;

1 FIG. 4 is a top plan view, partly in section, as taken along the line 4-4 of FIG. 2 showing the cover in its closed position;

FIG. 5 is a partial front elevational view asseen from the line 5-5 of FIG. 2;

FIG. 6 is an enlarged detail view of the-portion of the i apparatus shown within the circle 6 of FIG. 2;

FIG. 7 is a front view of the detail shown in FIG. 6 as viewed from the line 7-7 thereof;

FIG. 8 is an enlarged view of the area inscribed within the circle 8 of FIG. 4;

FIG. 9 is an enlarged transverse vertical sectional view as taken along the line 9-9 of FIG. 2;

FIG. 10 is a side elevational view of a modified form of the apparatus of the present invention showing the foldable gate of the charging hopper as being a substantially self-contained part of the hopper;

FIG. 11 is a side elevational view of the modified apparatus of FIG. 10 showing the gate folded or jackknifed into its open position;

FIG. 12 is a top plan view of the modified apparatus shown in FIG. 10 'as viewed from the line l2I2 of FIG. 10;

FIG. 13 is a partial front elevational view of the apparatus as viewed from the line 1313 of FIG. 12;

FIG. 14 is a transversesectional view of a portion of the apparatus as taken along the line l414 of FIG. 10;

FIG. 15 is an enlarged side elevational view of the portion shown within the circle 15 of FIG. 10; and

FIG. 16 is a sectional view as taken along the line 16-16 of FIG. 16.

Referring now more particularly to the drawings, FIG. 1 shows the application of the present invention to an incinerator, designated generally by the reference numeral 10, of any conventional construction having a furnace chamber 11 equipped with grates 12 for burning refuse deposited upon the grates by way of a charging hopper 13 having a depending throat or chute 14 leading to the grates. The gases of combustion are normally drawn rearwardly out of the furnace chamber for discharge to atmosphere under the influence of an electric motor driven suction fan or blower 15 located at the base end of the exhaust stack 16. In the incinerator illustrated in FIG. 1, an auxiliary exhaust vent 17 opening to atmosphere is provided in the roof of the furnace chamber just ahead of the exhaust stack 16 for effecting a natural draft exhaust of the combustion gases from the furnace chamber in the event of an emergency failure of operation of the motor driven blower 15.

10mm. (M (It Both the refuse charging hopper l3 and the auxiliary gas discharge vent 17 are provided with shiftable covers or gates respectively designated 18 and 19, each of which gates is constructed in accordance with and embodies the principles of the present invention. The refuse to be burned in the incinerator is elevated by any suitable means, as by an elevator type grab bucket (not shown), to a point just above the incinerator charging hopper and then deposited into the hopper from whence it drops by gravity into the furnace chamber and onto the grates for movement of the residual ash and other unburned products of combustion to and eventual discharge thereof at a suitable discharge point, such as a channel having therein a suitable ash conveyor mechanism (not shown).

When the blower is in normal operation the closure gate 19 for the auxiliary natural draft exhaust vent 17 is, of course, maintained closed, as is the closure gate 18 for the charging hopper 13 except for the intervals when the gate 18 is necessarily open for delivery of refuse into the charging hopper. So long as the charging hopper and its throat are substantially filled with rubbish to be incinerated, as is the case when the rubbish is being fed more or less continuously into the hopper 13, there is little likelihood of a back draft being created sufficient to interfere with efficient exhaust of the gases of combustion through the stack 16. Should, however, the hopper throat be free of rubbish during operation of the incinerator then there may result an undesired back draft and to prevent this the charging hopper gate 18 is desirably maintained closed at all times that the charging hopper and its throat are substantially free of rubbish.

The closure gates 18 and 19, although employed for different purposes in the incinerator as shown in FIG. 1, are essentially similar in construction and operation and thus only the charging gate 18 and its associated supporting structure and operating parts, will now be described in detail.

Referring more particularly to FIGS. 2 and 3 which illustrate one embodiment of the present invention, it will be observed that the closure gate 18 is designed to be shifted into closed or open position across the opentop of the incinerator charging hopper 13. It will be noted also that this hopper 13 is provided with downwardly converging opposite side walls 21-21 and downwardly converging front and rear walls 2223 (as see FIG. 4), all of which are relatively so upwardly extended as to provide an open top disposed in a common plane which slopes downwardly and forwardly lengthwise of the incinerator.

Secured to and extending lengthwise along the opposite side walls 2l-2l of the hopper in vertically spaced, parallel relation to the opposite side edges of the open top of the hopper are a pair of I-beams 24-24 or other such structural elements which respectively support a pair of rails or tracks 25-25 of inverted V- shaped cross-section. These rails 25-25 are so structurally supported by the l-beams as to not only extend in an inclined plane paralleling the inclined plane of the top edges of the hopper but also be disposed inboard of the top edges of the side walls of the hopper, as is best shown in FIG. 7.

The closure gate 18 comprises a pair of steel plate sections 26-27 which are suitably hinged together, as at 28, along a line extending transversely across the charging hopper whereby the two sections of the gate may be folded toward one another about their hinge line into their relative position best shown in FIG. 3. These hinged sections 26-27 of the cover or gate are each substantially of the same width as the overall width of the open top of the charging hopper, while their combined length is substantially equal to the length of the hopper top as measured from the front to rear ends thereof, in consequence of which the two sections of thecover when fully extended for flatwise disposition over the charging hopper, serve to completely close off the open top of the hopper.

Rigidly secured to the fore end of the front section 26 at each of its opposite sides is a strut assembly 29 having suitably joumalled thereon a V-grooved roller wheel 30 adapted to rest on and ride along one of the inverted V-shaped rails 25-25 extending along the opposite side walls of the hopper. Each of these roller wheels 30-30 is located forwardly beyond the fore end of the gate front section 26 upon which is mounted, it being noted in this connection that the rails or tracks 25-25 which are engaged by the roller wheels 30-30 also extend forwardly of the hopper for a distance sufficientto support these roller wheels when the latter are in their most forwardly advanced position for closure of the hopper as shown in FIG. 2.

It will be observed also that the upper edges of the forward extremities of the rails 25-25 are each downwardly inclined, as at 31, relatively to the upper edges of the main lengths of the rails whereby, when the gate is expanded into its hopper closing position, as see FIG. 2, the roller wheels 30-30 are lowered a distance sufficient to not only hold the same in gate closing position but also to insure full and complete contact of the expanded gage with the top edges of the charging hopper to effectively seal closed the open top of the latter The downwardly inclined forward extremities 31 of the tracks 25-25 also serve importantly as cams operating upon the roller wheels 30-30 to quickly break the seal between the front end of the hopper and its closure gate when the latter is jackknifed into its open position by the means now'to be described.

Secured to each of the opposite sides of the rear section 27 of the hinged charging gate 18 is a rearwardly projecting structural beam 32 having welded thereto a block 33 (as see FIG. 9) through which extends a shaft 34 which is keyed to the block 33 by a pin 35. The opposite projecting end portions of each of the shafts 34-34 are respectively rotatably joumalled in a pair of suitable journal boxes 36-36 which are fixedly secured to a support 37 extending transversely across and regidly secured to an upright beam 38 securely mounted upon the top of the incinerator in rearwardly spaced relation to the charging hopper 13. Also keyed, as by the pin 39, to a projecting end of each of the shafts 34-34 is a bell-crank lever 40 forming an obtuse angle with the plane of the charging gate rear section 27, the latter being thus provided upon each of its opposite sides with one of said bell crank levers as a relatively fixed part of said rear section 27.

Each of the upright beams 38-38 mounts an inwardly presenting bracket assembly 38a to which is suitably pivotally connected, as at 40a, a fluid pressure cylinder 41 having a piston rod 42 pivotally connected, as at 43, to the free end of each bell crank lever 40. Any suitable means (not shown) may be employed for simultaneously controlling the operation of the two fluid pressure cylinders 4l--41 and thus effecting retraction and extension in unison of the cylinder piston rods 4242. If desired, the bell crank levers may be commonly shafted and operated in unison manually or by power-driven means, such as a reversible electric motor suitably coupled to the oscillatable shaft or shafts of the bell crank levers, in which latter case the operation of the motor would be controlled by limit switches to limit the desired movement of the foldable gate into and out of its completely open and shut positions.

It will be apparent that upon extension of the piston rods 4242 under the fluid pressure exerted thereon, the bell crank levers 4040 are rotated downwardly about the axes of the shafts 3434 with resultant rotation of the latter in their journals to cause the rear plate 27 of the charging gate to rise i.e., swing clockwise as viewed in FIGS. 2 and 3) into its more or less vertical position shown in FIG. 3. As the gate section 27 is thus raised, it draws up with it its hingedly connected front section 26 to thereby cause the charging gate to assume its jack-knifed position shown in FIG. 3. As the rear section or plate 27 of the charging gate is raised as just described the roller wheels 3030 of the front section ride up and off of the inclined front end portions of the tracks -25 to thereby initially raise the fore end of the front gate section 26 free of the front end of the hopper, after which the wheels are then free to move along the main lengths of their tracks to the rearmost position shown in FIG. 3 to raise the front section of the gate and move it backward toward its simultaneously rising hingedly connected rear section 27.

Preferably, the undersurface of the gage 19 is marginally provided with a gasket 44 of asbestos or other suitable sealing material which is compressible against the top edges of the hopper under the weight thereon of the charging gate to effectively seal closed the open end of the hopper when the gate or cover is in its fully closed position. The inclined front end portions 3131 of the roller wheel tracks serve as depressions for accomodating the wheels when the same are in their foremost position and thus allow for the weight of the closed gate to compress the gasket along the full perimeter of the open end of the hopper and so provide a tightly sealed closure for the hopper. Also, preferably, one or both of the abutting edges of the gate sections 26 and 27 in the spaces not occupied by the hinges 28 therebetween are provided with compressible gasketing material, as at 44a in FIG. 8, to seal tight the hinged joint between the gate sections when the latter are flattened into their co-planar hopper-closing condition.

When the fluid pressure cylinders 4141 are relieved of fluid pressure to thereby permit retraction of their piston rods 42-42, the jack-knifed gate is free to expand or unfold into its flattened hopper closing condition as shown in FIG. 2, this reverse closing action being aided by gravity acting under the weight of the gate to cause it to unfold as the roller wheels 30 freely move forwardly along their downwardly inclined tracks into their final depressed position shown in FIG. 2.

An important feature of the present invention is the fact that when the charging gate is folded or jackknifed into its open position as shown in FIG. 3, the rearwardly and upwardly inclined front gate section or plate 26 serves as an upward extension of the inclined rear wall 23 of the hopper and so provides an auxiliary chute surface for guiding rubbish into the hopper with minimum undesired spraying of the same outside of the hopper.

Also, by locating the roller wheel tracks inboard of the top side edges of the hopper and by forming these tracks of inverted V-shape, as is most clearly shown in FIG. 7, both the tracks and the roller wheels associated therewith are maintained substantially dirt-free with the tracks themselves being virtually self-cleaning.

FIGS. 10 to 16, inclusive, illustrate a modified construction of the apparatus of the present invention, as well as certain details thereof which are equally applicable to the construction hereinbefore described.

In this modified construction, instead of providing a supporting structure for the gate and its operating means which is more or less structurally independent of the hopper and which requires separate mounting thereof upon the incinerator building itself, the fluid pressure operating means for opening and closing the charging gate is designed as a more or less self-contained part of the charging gate itself, thereby enabling the charging hopper, the charging gate or cover and all of the operating mechanism for the latter to be assembled and installed as one complete unit.

Referring now more particularly to FIGS. 10 to 14 it will first be observed that the top edges of the charging hopper 13a are fitted with angle iron structural members 45 to reinforce and strengthen the same against possible damage to the hopper resulting from its being struck by the grab bucket normally employed to elevate the rubbish from a storage pit and dump it into the hopper. The outwardly projecting flanges 46 of the top reinforcing members extending along opposite sides of the hopper project outwardly beyond the side edges of the hopper to an extent sufficient to serve as shields for deflecting rubbish spilled outside of the hopper outwardly away from the underlying gate roller wheel tracks to thereby maintain the latter free of such debris as might interfere with free movement of the wheels along the tracks. Since the upwardly presenting ridges 47 of the reinforcing angle members 45 are relatively sharp, they serve in and of themselves to prevent to a maximum degree any such accumulation of debris along the top edges of the hopper as might interfere with proper seating of the gate in its fully closed position, thereby permitting the sharp ridges to be firmly pressed into the asbestos gasket 48 lining the underside of the gate, as in the case of the previously described gate, to provide an effective linear seal between the hopper and its closed gate. Any rubbish striking the reinforced top edges of the hopper, if not outwardly deflected by the outwardly presenting flanges 47, must perforce be diverted directly into the hopper by the inwardly presenting flanges of the angle members 46 and thus very little, if any, debris is deposited upon the wheel tracks 25a-25a.

As in the case of the previously described embodiment of the present invention, the front and rear sections 26a and 27a of the closure gate are respectively provided along each opposite side thereof with structural members extending freely beyond the fore and aft ends of the gate. Thus, the, gate front section 26a is provided at each side thereof with a downwardly and forwardly projecting strut 50 mounting upon its free end a roller wheel 30a, whilethe gate rear section 270 is provided at each side thereof with a rearwardly projecting strut 51 carrying at its free end a bracket assembly 52 for rigidly connecting each said strut 51 to a bell crank lever 40a. Each of the rearwardly extending struts 51 and its associated bell crank lever 40a is keyed, as in the case of the previously described embodiment, to a shaft 27a,'which shaft, in the present instance, is rotatable in a pairof journal boxes 36a-36a suitably mounted upon a suitable bracket assembly 53 welded or otherwise rigidly secured to Y the rail supporting beams 24a--24a respectively extending along and secured to opposite'sides of charging hopper 13a.

Also pivotally secured to and carried by each of the rail supporting beams 24a-24a is a fluid pressure cylinder 41a having its piston rod 42a pivotally connected, as at 43a, to the free end of its associated bell crank lever 40a.

When the fluid pressure cylinder 41a is energized to pull its piston rod inwardly of the cylinder, as shown in FIG. 11, the bell crank lever will be rotated clockwise to raise the gate rear section 27a upwardly from its closing position over the top of the charging hopper and simultaneously draw the wheeled front section 26a of the gate rearwardly along the inclined wheel tracks 25a25a until the gate assumes its jack-knifed open position shown in FIG. 11. As in the case of the previously described form of the invention, upon relief of the fluid pressure exerted upon the cylinder piston rod, the gate is free to move forwardly and downwardly along the inclined wheel tracks until it assumes its fully expanded or unfolded flat condition as shown in FIG. to completely seal closed the top of the charging hopper 13a.

As most clearly appears in F l0. 12, the fluid pressure operating mechanism as just described is provided at each of the opposite sides of the gate or cover and it will be understood that any suitable means may be employed for effecting simultaneous operation of said mechanism and rotation of their respectively associated bell crank levers in unison.

It will be noted that the front ends of the roller wheel tracks 25a25a are each rounded off, as at 54, to provide depressed seats for the roller wheels when they reach the limit of their forward travel downwardly along the tracks. These depressions at the front extremities of the tracks permit the wheels to drop downwardly at the end of their gate-closing movement sufficiently to insure that the gasket extending marginally about the underside of the gate positively engages the upwardly presenting relatively sharp ridge 48 along the full perimeter of the open top of the charging hopper. Also, as in the case of the beveled fore end portions of the tracks of the previously described construction, the rounded front end portions of the tracks 25a 25a serve as cams to more or less quickly raise the fore end of the gate from section out of engagement with the edge of the hopper at the front end thereof and so break the seal to facilitate free movement of the gate along the main portions of the tracks towards its jackknifed, fully open position shown in FIG. 11.

In order to insure for proper seating of the cover to seal the same tightly closed against the ridged top of the charging hopper, means are provided, as best shown in Fig. 16, for vertically adjusting the axes of rotation of the roller wheels with reference to plane of the underside of the gasketed cover when the latter is in its fully closed position as shown in FIG. 10. In this arrangement as shown, the roller wheels 30a30a are revolubly mounted upon a stub shaft 55 formedas an eccentric extension of a cylindrical main body part 56 which is keyed in any desired rotatably adjusted position within a bearing block 57 by means of a set-screw 58. This bearing block is welded or otherwise rigidly secured to the freely extending front end of the roller wheel support assembly 29 and upon suitable rotatable adjustment of the shaft part 56 within the block 57 the eccentric shaft 55 for the wheel may be, raised or lowered to the degree necessary for full sealing engagement of the cover with the top end of the charging hopper when the cover is in its fully closed position.

Of course, it will be understood that any suitable I means may be employed for effecting desired vertical adjustment of the axes of rotation of. the roller wheels and that such adjusting means for the roller wheels may be provided in the previously described embodiment of the present invention.

The hopper charging gate of the present invention may be provided, if so desired, with swingable side covers such as are shown and described in our above mentioned co-pending application, the construction, operation and function of which are incorporated herein by reference to said co-pending application.

It will be understood further that-the present invention is susceptible ofvarious changes and modifications which may be made from time to time without departing from the principles or real spirit thereof, and it is accordingly intended to claim the same broadly, as well as specifically as indicated in the appended claims.

What is claimed as new and useful is:

l. A cut-off gate of the character described for use in an incinerator comprising, in combination, an opentopped hopper for introducing successive charges of rubbish to be burned into the incinerator having a perimetrally continuous planar top edge, a pair of transversely spaced parallel side rails respectively disposed on opposite sides of and in straddling relation to said unit, a gate shiftable onto and off of said top edge of the hopper to selectively open and close the top of the hopper, said gate being formed of a pair of relatively foldable frontal and rear sections hinged together along a transversely extending hinge line, a pair of roller wheels journalled on the frontal section of said gate at the fore end thereof adapted respectively to ride along said rails, and power-operated means operative to effect relative folding of said hinged gate sections about their said hinge line to thereby draw the wheeled frontal section of the gate along said tracks and simultaneously cause said sections to be jack-knifed into hopper-opening position, said top edge of the hopper being fitted with inverted V-shaped members having flanges extending downwardly and outwardly of the hopper top for deflecting rubbish spilling over the edges of the hopper during charging thereof outwardly of and away from said gate-supporting rails.

2. A cut-off gate as defined in claim 1 wherein said top edge of said hopper is disposed in a plane inclined upwardly from the front to the rear end of said hopper and said rails are disposed in an inclined plane spaced below and in parallel relation to the inclined plane of said hopper top edge.

3. A ctu-off gate as defined in claim 2 wherein said gate sections when in their jack-knifed hopper-opening position are relatively so angularly related with respect to each other and to said inclined rails as to enable them to shift by gravity along said rails and simultaneously be unfolded into coplanar relation for flatwise sealing engagement with the top edges of said hopper to seal the same closed.

4. A cut-off gate as defined in claim 1 wherein said gate sections when unfolded from their jack-knifed hopper-opening position upon reverse travel of the wheeled front section along said rails are adapted to be seated flatwise in coplanar relation against the top edge of said hopper to seal the same closed.

5. A cut-off gate for an incinerator charging hopper as defined in claim 1 wherein said gage-supporting rails are respectively mounted inboard of said outwardly extending rubbish-deflecting flanges.

6. A cut-off gate as defined in claim 1 wherein the frontal extremities of said side rails are depressed to permit lowering of the wheels of the gate below their normal plane of travel along the rails whereby to correspondingly lower the front end of said second section of the gate into seated engagement with the front top edge of the hopper as the gate reaches the forward limit of its travel along said rails. 7. A cut-off gate as defined in claim 1 wherein said frontal section of the gate when the latter is jack-knifed upwardly into its hopper opening position serves as a chute for deflecting back into the hopper rubbish which would otherwise spill over the rear edge of the hopper during the charging thereof with such rubbish.

8. A cut-off gate as defined in claim 1 including means for adjustably varying the positions of the roller wheel axes of rotation relatively to the gate and thereby adjust the seating engagement of the gate upon the top edges of the hopper. 

1. A cut-off gate of the character described for use in an incinerator comprising, in combination, an open-topped hopper for introducing successive charges of rubbish to be burned into the incinerator having a perimetrally continuous planar top edge, a pair of transversely spaced parallel side rails respectively disposed on opposite sides of and in straddling relation to said unit, a gate shiftable onto and off of said top edge of the hopper to selectively open and close the top of the hopper, said gate being formed of a pair of relatively foldable frontal and rear sections hinged together along a transversely extending hinge line, a pair of roller wheels journalled on the frontal section of said gate at the fore end thereof adapted respectively to ride along said rails, and power-operated means operative to effect relative folding of said hinged gate sections about their said hinge line to thereby draw the wheeled frontal section of the gate along said tracks and simultaneously cause said sections to be jack-knifed into hopper-opening position, said top edge of the hopper being fitted with inverted V-shaped members having flanges extending downwardly and outwardly of the hopper top for deflecting rubbish spilling over the edges of the hopper during charging thereof outwardly of and away from said gate-supporting rails.
 2. A cut-off gate as defined in claim 1 wherein said top edge of said hopper is disposed in a plane inclined upwardly from the front to the rear end of said hopper and said rails are disposed in an inclined plane spaced below and in parallel relation to the inclined plane of said hopper top edge.
 3. A ctu-off gate as defined in claim 2 wherein said gate sections when in their jack-knifed hopper-opening position are relatively so angularly related with respect to each other and to said inclined rails as to enable them to shift by gravity along said rails and simultaneously be unfolded into coplanar relation for flatwise sealing engagement with the top edges of said hopper to seal the same closed.
 4. A cut-off gate as defined in claim 1 wherein said gate sections when unfolded from their jack-knifed hopper-opening position upon reverse travel of the wheeled front section along said rails are adapted to be seated flatwise in coplanar relation against the top edge of said hopper to seal the same closed.
 5. A cut-off gate for an incinerator charging hopper as defined in claim 1 wherein said gage-supporting rails are respectively mounted inboard of said outwardly extending rubbish-deflecting flanges.
 6. A cut-off gate as defined in claim 1 wherein the frontal extremities of said side rails are depressed to permit lowering of the wheels of the gate below their normal plane of travel along the rails whereby to correspondingly lower the front end of said second section of the gate into seated engagement with the front top edge of the hopper as the gate reaches the forward limit of its travel along said rails.
 7. A cut-off gate as defined in claim 1 wherein said frontal section of the gate when the latter is jack-knifed upwardly into its hopper opening position serves as a chute for deflecting back into the hopper rubbish which would otherwise spill over the rear edge of the hopper during the charging thereof with such rubbish.
 8. A cut-off gate as defined in claim 1 including means for adjustably varying the positions of the roller wheel axes of rotation relatively to the gate and thereby adjust the seating engagement of the gate upon the top edges of the hopper. 